A bonding pad includes multiple metal layers, insulation layers filled between the multiple metal layers, and a fixing pin coupled between the uppermost metal layer, where a bonding is performed, and the underlying metal layers. Peeling of the bonding pad can be prevented during the ball bonding by forming the fixing pin coupled to the edges of the bonding pad. The upper portion of the fixing pin is formed in a disk shape and a ball portion of the fixing pin is fixed by slits such that the peeling of the bonding pad can be further prevented.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for fabricating a bonding pad, the method comprising: forming a first insulation layer; forming a plurality of slits over the first insulation layer; forming a second insulation layer over the slits; partially etching the second insulation layer and the first insulation layer to form a contact hole defined in an interval between the slits; forming a fixing pin filling the contact hole; and forming a metal layer coupled to the fixing pin, wherein a bonding is to be performed on the metal layer.
2. The method of claim 1 , wherein forming the contact hole comprises: forming a contact mask defining the contact hole over the second insulation layer; primarily etching the second insulation layer to a predetermined depth to form a first contact hole having a width greater than a width of the contact hole defined in the contact mask; forming a second contact hole by secondarily etching the second insulation layer under the first contact hole until the second insulation layer formed between the slits is removed; and forming a ball-shaped third contact hole by etching the first insulation layer formed under the second contact hole.
3. The method of claim 2 , wherein the primary etching is performed by a wet etch process, and the secondary etching is performed by a dry etch process.
4. The method of claim 2 , wherein the first contact hole is formed in a disk shape, the second contact hole is formed in a pillar shape, and the third contact hole is formed in a ball shape so that the diameter of the third contact hole is greater a size of an interval between the slits.
5. The method of claim 2 , wherein forming the third contact hole is performed by an isotropic etch process.
6. The method of claim 1 , wherein the fixing pin comprises a conductive layer.
7. The method of claim 1 , wherein the fixing pin comprises a tungsten layer.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
June 30, 2008
October 5, 2010
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